Apparatus for and method of recording and reproducing sounds



April 9, 1929. B. KWARTIN 1,708,476

APPARATUS FOR AND METHOD OF RECORDING AND REPRODUCING SOUNDS Filed March 22, 1928 INVENTOR:

ATTORNEY I Patented Apn 9, 1929.

' UNITED STATES PATIENT orrics.

BERNARD xwanrrmor PHILADELPHIA, PENNSYLVANIA.

APPARATUS FOR AND EMHOD OF RECORDING AND PRODUCING SOUNDS.

application filed larch 22, 1928. Serial No. 268,749.

This invention relates generally to the re cording and reproducing of sound effects and more particularly to improvements in an appai'utus for and method of recording and reproducing sounds such that a more natural reproductiorr is obtained than has been possi hle heretofore.

' This invention, which is particularly adapted for the reproduction of band, orchestral, or other ensemble or solo instru-.

'lucntal or vocal selections in a manner which is better, clearer and more satisfactory than is now-possible, is primarily concerned with the idea of combining the two basic principles now generally employed in the recording and reproduction of sound. The first of these principles and the one most generall employed is herein termed the frictional principle or process 'wherein a needle or stylus is arranged to operativcly engage the playing surface of a record, this record being in the form of a continuous film, wax dlsc or cylinder, or the like, and the playing surface thereof being provided with the usual sound wave impressions. The reproduction of sound in this arrangement is obtained through the vibrations set up in the needle or stylus as it travels over the impressions formed on the record and transmitted to a suitable diaphragm secured to said needle. The second of these principles and the one which is more or less generally employed n connection with the simultaneous reproduction of pictures and sounds is herein termed the non-frictional principle or process. In this .non-frictional process, the sound waves as originally produced by the instruments or voices are converted into electrical currents which in turn produce light,

variations of intensities corres diilerent sounds. By employlng these-light variations, a photographic record of the sounds as originally produced is obtained upon a film. To reproduce the sounds, this film upon 'which the sound effects have'been pholographically recorded is caused to travel between a suitable light source and a photoelectric cell in such manner that the light variations which are so produced are reconvcrted into electrical variations whichlatter onding to the in turn cause vibrations to be set up in the diaphra m of a sound reproducer. It will be seen t at this non-frictional rocess is entirely different from the frictional process in that no needle or like element is employed for frictionally enga ing the sound record in order to produce t e necessary sound impressions during the recording proces or to produce a vibration of the reproducer diaphragm during the reproducing process. In

vs have each certain distinct a is accordingly an object of this invention to so combine and use the two systems that the advantages of one supplement those of the other in such manner that it becomes possible to reproduce the sounds more naturally than has ever been possible before.

In both systems the reproduction of sounds is imperfect to a certain extent in each, especially in the reproduction of ensemble music and ordinary speech, thereby necessitatin an exaggerated and unequal amplification 0% the sounds with the result that the ori a1 character of these sounds are so distorteiftl iat they sound unnatural when finally re reduced. Due most probably to certain in erent characteristics of these systems, I have found that while one system is best suited. for reproducing sounds of ascertain character, the other system is equally suitable for reproducing sounds of different character, through neithersystem is capable of eflicient- 1y reproducing all sounds. It thus becomes an object of this invention to so combine and utilize the two systems that they will simultaneouslv record and reproduce sound eflects of sounds which are rich in overtones (harmonmiddle-pitched strings, brass, metal percusno matter what character in 'a most efiicient and natural manner. i That there is an appreciable difi'erence in ics) and those which are poor in overtones is well known. Examples of sounds rich in overtones arethose'produced by high and sion instruments and properly-placed human voices, while examples of sounds poor in overtones are those produced by low-pitched strings, wood-wind instruments, drum and. From personal poorly-placed human voices. experiments and observations, I have found that sounds rich in overtones are best reproduced by the frictional system, whereas sounds poor in overtones are best reproduced by the non-frictional system. It will accordi'ngly appear that by .utilizing both systems simultaneously, a morenatural reproduction of the sounds may be obtained, this being especially true of ensemble music wherein instruments are employed which produce sounds of rich and poor overtones, it being an object of this invention to so distribute these sounds that those rich in harmonics will be recorded and reproduced by the frictional system, while those poor in harmonics will be recorded and reproduced by the non-fricabove are the r tional system. In this connection it will be understood, of course, that both systems are intended to be operated simultaneously and in synehronism, each instrument or voice, however, being individually treated in accordance with the character of sound pro-v duced thereby.

Other objects ancillary to those stated 'eproduction of ensemble music where the quality of each sound or note is equal'to its quality when reproduced in solo; the attainment of a multiplied volume without that exaggerated amplification which causes distortion of the sounds; and the recording and reproduction of simple speech and solo music in such manner that the sounds or notes which are rich in harmonics will be recorded upon and reproduced by the frictional type of record while those sounds which are poor in harmonics will be recorded upon and reproduced by the non-frictional type of record, the'result being that a better and more natural reproduction of speech and solo music will be possible.

A further object of this invention is the application thereof to the apparatus for and method of simultaneously but individually recording the different sounds produced in ensemble as disclosed in my copending applications, Serial No. 212,646, filed August 13, 1927, and Serial No. 237,322, filed Dec. 2. 1927 In these copending applications I have disclosed the idea of utilizing microphonesby means of the tion' of a sound of particular pitch. The

present invention is a still further development along these lines in that in the present instance the different sounds are distributed for recording upon and reproduction by either the frictional or non-frictional record pitch; In other words, it now becomes pos-,

sible to record and reproduce a plurality of sounds of different pitch characteristics all of which are rich in overtones or harmonics frictional system at the same time that a plurality of other sounds also of different pitch characteristics but all of which are poor 1n overtones or harmonics are recorded and reproduced by means of the nonfrictional system.

Other objects, and objects relating to details of arrangement of the apparatus and the method of utilizing the frictional and nonfrictional systems whereby to efliciently record and more naturally reproduce solo and ensemble music, will appear more fully hereinafter.

The invention consists substantially in the combination and relative location and arrangement of apparatus, as well as in the method of using the same all as will appear more fully in the following specification, as shown in the accompanying drawings, and as finally pointed out in the appended claims.

'In the accompanying drawings which are shown for illustrative purposes only:

Figure 1 1s a diagrammatic plan View of a frictional and a non-frictional recording mechanism arranged and connected for synchronous operation in accordance with the principles contemplated by this invention;

Figure 2 is a similar View of mechanisms arranged and connected for synchronously reproducing the sounds as recorded by the arrangement shown in Figure 1;

Figure 3 is a fragmentary view of a multiple sound record obtained by means of the non-frictional recording mechanism; and

Figure 4 is a view of a multiple sound record obtained by means of the frictional rccording mechanism.

Referring now to the drawings, and more particularly to Figure 1 thereof, which illustrates more or less,diagrammatically'au arrangement of mechanisms for simultaneously recording a plurality of sounds as produced by different instruments and voices playing or singing together in concert, these mechanisms being arranged for synchronous operation in such manner that the individual identity of each sound is at all times preserved, it will be seen that this recording ar rangement employs a camera 10 or similar apparatus for photographically recording upon a film sounds which are poor in overtones, such as those produced by low pitched strings, wood-wind instruments, drums, and poorly placed human voices. This camera or recording appartus 10 employs the usual motion picture film 11, which latter is unreeled from one reel (not shown) for subsequent winding upon another reel (not shown) during the process of recording the sound variations thereupon. The mechanism 10, which is termed herein as the non-frictional recording mechanism, is essentially similar in construction and in operation to that which has been described in detail in my co-pending application, Serial No. 237,322, and referred to above. Secured tothe inside surface of the rearwall of the camera and extending transversely thereacross is an opaque plate 12 provided with one or more small slits or openings 13 therein. In theparticular arrangement shown in Figure 1, these openings 13 are four in number and are spaced apart equidistantly, such that four separate sound records may be photographically recorded upon the film. Mounted upon the rear wall of the camera 10 in any suitable manner are a plurality of recording lamps 14 for throwing light rays of varying intensities upon'the film, these recording lamps being energized by electrical variations produced through 1; e use of microphones in a manner well known in the art. 'These recording lamps 14 are equal in number to the number of openings 13, each lamp being positioned di-' rectly behind its respective opening such that the fluctuating light rays emanating from any one of these lamps will produce a record upon the film of the sounds influencing the particular lamp. By properly proportioning the openings 13, the width and length of the beams of light that are directed on the film by the several recording lamps may be rigidly held to the roper limits. It will furtherbe seen that t e provision of a number of recording lamps arranged to be individually energized makes it possible to produce a corresponding number of sound records upon a single film, each of .which records is produced by the action of different sound waves upon a'number of microphones. The moving parts ofthe camera 10'arc actuated b a motor 15 through the driving shaft 16, t is motor 15 being also operative, through the shaft 17 to drivea second sound recording apparatus designated. generally by the reference numeral 18. This second recording apparatus 18 is of the frictionaltype wherein a matrix 19 carried upon a rotatable turntable 20-is operatively engaged by the stylus of a sound reproducer 21, the

- latter being preferabl provided witha horn 22 for collecting and irecting certain sounds to saidsoundre roducer. In Figure 1, the frictional recor ing apparatus 18 is shown as being provided with two sets of sound recording devices operable upon a single matrix whereby to produce upon said matrix two separate sound records in accordance with the principles outlined in my co-pending application, Serial N 0. 212,646, and referred to above. It will be understood, of course, that only one or more than two of such recording devices may be employed in connection with the frictional recording apparatus depending solely upon the degree of refinement to be had. Due to the fact that the frictional recording apparatus 18- and the non-"frictional apparatus 10 are commonly operated by the motor 15 through the shafts 16 and 17, the said apparatus are at all times in absolute synchronism, the result being that the frictional and non-frictional sound records are produced simultaneously.

It is well known that where a number of instruments are being played in concert, it is impossible, through the use of a single microphone or sound reproducing device, to produce a single record of the sounds created by said instruments which is true and faithful to the sounds as originally and individually ferent sounds each of different identity, tone; as or timbre. It is for this reason that the nonfrictional recording apparatus 10 is provided with a number of recording lamps for producing upon a single. photographic film a corresponding number of individual sound records, each of these records being sound or sounds of substantially similar itch value. For the same reason, the frictional recording apparatus 18 is provided with a number of sound recording devices 21 for recording upon a single record a corresponding number of sound records, each of these sounds being'of. a sound or sounds of substantially similar pitch value. In order to properly segregate the sounds of difierent 'pitch as'producedby vthe several nstruments when playing in concert, the diaphragms of the microphones 22f used in connection'with the non-frictional recording apparatus and the diaphragms of the sound recording de vices 21 used in connection with the fr1c-' tional recording apparatus are of different diameters and mass, the smallest diaphragms pitch while the largest diaphragms are do.- signed to take the sounds of lowest p1 tch. Diaphragms of intermediate size and werght are adapted to take sounds of intermediate pitches. This distribution of sounds of different pitch' by the use of microphones or sound reproducingdevices having diaphragms of different size and we ight forms no part of the present invention, the latter being especially concerned with the distribution of sounds according to their richness or ofaill)

being designed to take the sounds of highest voices, that poorness in overtones, it being understood that certain sounds may be rich or poor in overtones irrespective of their pitch characteristics. As has been stated above, I have found, from personal experiments and observations, that sounds rich in overtones are best recorded and reproduced by the frictional system, while sounds poor in overtones are best recorded and reproduced by the nonfrictional system.

It will accordingly appear by utilizing both systems-simultaneously and operating them in synchronism by means of the arrangement shown in Figure 1, a more natural reproduction of the sounds may be obtained. Accordingly, it is my idea to so arrange the instruments which produce sounds rich in harmonics, such as high and middle pitched strings, brass, metal percussion instruments, and properly placed human the sounds emanating therefrom will be recorded upon the frictional type of record 19 by means of the recording appa ratus 18, while the instruments which produce sounds poor in harmonics, such as low pitched strings, wood-wind instruments, drum, and poorly placed human voices, are so placed or arranged that the sounds emanating therefrom will be photographically recorded upon the film 11 by, means of the recording apparatus 10. Because of the fact that those recording apparatus are operated simultaneously and in by the motor 15 or in any other suitable manner, all of the instruments or voicin will be recorded synchronously, each instrument or voice, however, individually treated in accordance with the character of sound produced thereby, all of the sounds rich in overtones or harmonics being recorded upon the frictional type of record 19 while all of those r in harmonics or overtoms will be recorded upon the film 11.

Figures 3 and 4 show respectively the two different records simultaneously produced by the arrangement shown in Figure 1, these records being complements one of the other. It will be observed that the non-frictional record shown in Fig. 3 comprises a single strip of photographic film upon which have been simultaneously recorded a plurality of a sound records 23, each of these records being of sounds of different pitch characteristics but being all poor in harmonics. 4 shows a record as produced by the frictional recording apparatus, this record comprising a single disc upon which have been simultaneously recorded a plurality of sound reeords 24, each of these latter records being of sounds of difierent pitch characteristics but being all rich in harmonics. It is to be understood, of course, that a greater or laser number of individual sound records may be made upon each of the records shown in Figs. 3 and 4, the number of such records being dependratus comprises a box 30 containing the photographic film record 11. Extendingltransvcrsely from side to side of the box 30is an opaque partition 31 provided with small slits or openings 32 corresponding in number and registering with the number of individual sound records on the film 11. A suitable light source 33 is provided for each of the slits or openings 32 and is arranged with respect to its respective opening in such manher that the rays of light emanating therefrom are directing upon the particular sound record passing in front of said opening. The sounds as recorded u on the film 11 are reproduced by means 0 a photo-electric cell 34 or similar device which is influenced by the fluctuating light variations caused by the several sound records passing their respective light sources 33. A separate photo-electric cell is employedfor eachindividual sound record. As is well known in the art, these photo-electric cells have the property of converting light rays into electrical variations, which latter in turn influence the diaphragms of the loud speakers 35. These loud speakers 35 are provided with diaphragms of different sizes and weights exactly as in the case of the microphones used in the arrangement 'for recording the sounds upon the photosubstantially similar to the recording apparatus 18 shown in Figure 1, the operation.

. 7 0 The frictional reproducing aparatus 26 is thereof being however reversed. As in thel. V

case of the non-frictional apparatus 25, this number of sound reproducing devices having 125. frictional apparatus 26 is also provided witha r sound reproducing devices 36 being so designed that each is best adapted to reproduce sounds of particular pitches. In other words, the diaphragm of any one of the sound reproducing devices 36 which is influenced by one of the sound records 24 on the record 1%) is so designed as to be most efficiently responsive to the same frequency of vibration as was the diaphragm of the microphone used in re-.

cording that particular one of the sound records 24.

Due to the fact that the sounds of poor overtones, irrespective of variations in pitch, have been recorded upon the film 11, while those'of rich overtones, also irrespective of variations in pitch, have been recorded upon the record 19, amore perfect reproduction of the sounds willbe obtained without losing any of the identity, tone," characteristics or timbre of any of the sounds. It will be understood, of course, that while the invention has been "described in connection of rich overtones will be reeorded upon the record 19 while those of poor overtones will be recorded upon the film 11. I

It will be understood that various changes and n'lodifications of the arrangements of apparatus for and methods of recording and reproducing sounds as disclosed and described herein may be made without de art- -ing from the spirit or princi les' of this invention, and it is according y intended to claim the same broadly, as well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. In a sound recording and reproducing apparatus, in combination, means for photogra'phically recording upon a photographic 1m sound'vibrations which are poor in overtones, and means operable in synchronism with said first-mentioned means for frictionally recording upon a frictional record sound vibrations which are rich in overtones.

2. In a sound recording and reproducin apparatus for recording the sounds produced by one or more instruments or voices playing in unison, certain of the sound vibrations so produced being rich in overtones and others poor in overtones, in combination, means seectively responsive to the sound vibrations of poor overtones for recording the same upon one record, and means selectively responsive to thesound vibration of rich overtones for simutaneousli recording the same upon a second recor 0rd those which are ric 3. In a sound recording and reproducing apparatus for recording sounds certain vibrations of which are poor in overtones while others are rich in overtones, in combination, means selectively responsive to the sound vibrations of poor overtones for recording the same upon one record, means selectively responsive to the sound vibrations of rich overtones for recording the same upon a second record, and means for operatingthe aforesaid means in synchronism whereby to produce sound records which are supplements one of the other.

4. An apparatus forrecording sound vibrations certain of which are poor in overtones while others are rich in overtones comprising means selectively responsive to poor-in-overtone sound vibrations, means for photogra hically recording said poor-in-overtone vibrations upon a record, means selectively responsive to rich-in-overtone sound vibrations, means for frictionally recording said rich-inovertone vibrations upon a second record, and means for operating said frictional and nonfrictional recording means in synchronism such that therecords produced thereby together constitute a composite record of the combination, means for photographically recording upon a record those sound vibrations which are poor in overt-ones, means for frictionally recording upon a separate recsound vibrations whichare rich in overtones, and means for operating said frictional andnon-frictional recording means in synchronism such that the records produced thereby together constitute a composite record of the sound vibrations as originally produced. e

6. An apparatus for simultaneousl reproducing sound vibrations characterize in that the overtones thereof are both rich and poor, said apparatus comprising photographic means for individually reproducmg the sound Vibrations which are poor in overtones, frictional means for! individually re roducing the sound vibrations which are ric in over- Lones, and means for operating said frictional and photographic means in synchronism. I

7 The method of simultaneously recording sound vibrations difiering in overtone characteristics, certain of said vibrations being poor in overtones whileothers are rich in overtones, which consists in selectively recording those sound vibrations which are poor in resonance upon one record, and in selectively and simultaneously recording those vibrations 1 in overtones upon a separate record, the records so produced constituting conjointly a composite record of the sounds as originally produced. I

8. The method of simultaneously recording and reproducing sound vibrationsdiifering in rate record, said photographic and frictional overtone characteristics, certain of said-vibrarecording being performed synchronously, 1 tions being poor in overtones while others are and in simultaneously butseparately reprorich. in overtones, which consists in photo ducing the sound records so produced.

graphically recording those sound vibrations In testimony whereof, I have hereunto'afwhich are poor in overtones upon one record, fixed my signature.

in; frictionally recording those sound vibrations which are rich in overtones upona sepa- BERNARD KWARTIN. 

